The self-diffusion coefficient of liquid methane

Self-diffusion coefficients of methane have been calculated over a wide density range using the method of molecular dynamics. Methane intermolecular interactions were modelled using an m-6–8 potential with coefficients determined from viscosity data for the dilute gas. After adding a contribution to the diffusion coefficient due to the long-time behaviour of the velocity autocorrelation function, agreement with experimental data is within the estimated errors given for both the calculated values and the experimental data.